DIABETICS DRUGS
BIGUANIDES, SULPHONYLUREAS AND INSULIN
BIGUANIDES
Buformin
Metformin
Phenformin
Clinical effects
Metabolic effects (A profound lactic acidosis, serum bicarbonate is low and there is usually
a large anion gap)
Cardiac effects
Hypotension and tachycardia are common, Myocardial infarction has occurred secondary to profound acidosis.
Central nervous system effects
Nausea – vomiting are common in the early stages; delirium, sedation, coma, and seizures may all occur secondary to the acidosis.
Other effects
Hypothermia, acute renal failure, pulmonary oedema, pneumonia may all complicate the episode. particularly in delayed presentations.
Investigations
1.0 Blood concentrations
2.Biochemistry (Electrolytes, glucose, renal function, anion gap, arterial blood gas and lactate) 3.ECG should be performed
Severity
The following are associated with a less favourable outcome (mortality and morbidity):
Elderly (age >60)
Complicating medical conditions (e.g. ischaemic heart disease, respiratory disease) Renal failure
Hypotension (shock)
Diabetes
Low pH on presentation (pH<7.0) Low bicarbonate on presentation (HCO3 < 6.0 mmol/L) High lactate (> 17 mmol/L)
Treatment
- Supportive
- GI Decontamination (Oral activated charcoal should be given to all patients who present within 1 to 2 hours of ingestion as these drugs are quite slowly absorbed. There is unlikely to be any benefit from repeated doses of activated charcoal)
- Acidosis (Routine use of glucose and insulin, very slow and low doses of sodium bicarbonate if the pH is less than 6.9 – 7.0, and dichloroacetate if it is available.)
- Antidotes (Bicarbonate, Dichloroacetate, Glucose & Insulin
- Haemodialysis